1. Field of the Invention
The invention relates in general to an active matrix organic light emitting diode (AMOLED) panel, and more particularly to an AMOLED panel driven by a large current.
2. Description of the Related Art
Normally, in an AMOLED display, images are displayed by a large number of pixels on the AMOLED panel. Each pixel of the AMOLED panel is controlled according to a data signal so as to display the required luminance.
Referring to FIG. 1, a circuit diagram of a conventional AMOLED panel is shown. In an AMOLED panel 10, during a writing time period, a scan signal Scan outputted by a scan driving unit 14 turns on transistors T1 and T2 in the AMOLED pixel unit 11. Due to a current IData of the data driving unit 12, the same current IData is generated on the transistor T3. Owing that the transistors T3 and T4 form a current mirror structure, the transistor T4 generates a current IOLED proportional to the current IData. The transistor T4 outputs the current IOLED to a light emitting diode 16 to display the corresponding luminance. At the same time, the capacitor C is also charged to a corresponding voltage level.
Afterward, in a display time period, the scan signal Scan turns off the transistor T1 and T2 to electrically isolate the transistor T4 from the data driving unit 12. The voltage difference between the source and gate of the transistor T4 can be stabilized at the corresponding voltage level by the capacitor C. Therefore, the current IOLED can be maintained at a certain value stably. However, the above data driving unit 12 can provide only a limited current IData. If a larger current is to be required, the area of the data driving unit 12 has to be increased, thereby improving production cost.